Generally, a shoe includes an upper covering the top side and lateral side of a foot, and soles constituting the bottom of the shoe. In this case, the soles include an insole contacting the bottom of a foot, an outsole contacting the ground, and a midsole located between the insole and outsole.
In order to manufacture such a shoe, since parts made of various materials are fabricated and are then assembled into a shoe, there is a problem in that processes are complicated and thus it takes a lot of time and incurs high costs to manufacture the shoe. Further, since adhesives must be used, there is a problem in that the working environment becomes bad, and processes become complicated.
Recently, methods of inexpensively manufacturing a shoe using the same materials have been developed. However, since such a shoe is difficult to manufacture in one piece, an upper and soles are separately fabricated, and are then attached to each other, and thus adhesives are inevitably used.
In order to solve the above problems, Korean Unexamined Patent Publication No. 10-2001-99480, entitled “Mold for shoes and sandals manufactured using the same”, discloses a method of manufacturing one-piece shoes using a foot-shape moving core provided in a top mold.
This method is advantageous in that, since shoes are manufactured in one piece using the same materials, work can be conveniently performed, but is problematic in that the feeling or durability of the shoes manufactured using this method is problematic. That is, when shoes are manufactured using soft material, there is a problem in that the feeling is improved, but the portions contacting the ground are easily abraded, thus decreasing durability. In contrast, when shoes are manufactured using a material having high wear resistance, there is a problem in that durability is improved, but the feeling is deteriorated.
Further, the shoes manufactured in one piece are problematic in that, since they are manufactured using synthetic resin, which has poor air permeability, sweat and smell are generated when they are put on for a long time, thus deteriorating the feeling.